Machine for cutting tobacco and the like



Sept; 18, 1956 y Q. R. SCHREIBER MACHINE FOR CUTTING TOBACCO AND THE LIKE Original Filed April 4, 1950 FIG].

3 Sheets-Sheet 1 u Inventor Sept. 18, 1956 P. Q. R. SCHREIBER MACHINE FOR CUTTING TOBACCO AND THE LIKE 3 Sheets-Sheet 2 Original Filed April 4, 1950 Attorney Sept. 18, 1956 P- Q. R. SCHREIBER 2,763,307

MACHINE FOR CUTTING TOBACCO AND THE LIKE Original Filed April 4. 1950 3 Sheets-Sheet 3 Inventor lam/Of ll/V77 W sa/kE/KP,

Attorney United States Patent MACHINE FOR CUTTING TOBACCO AND THE LIKE Patrick Quintin Robert Schreiber, London, England, as-

signor to Robert Legg Limited, City Engine Works, London, England, a British company Original application April 4, 1950, Serial No. 153,809, now Patent No. 2,738,629, dated March 20, 1956. Divided and this application April 24, 1951, Serial No. 222,549

3 Claims. (Cl. 146-119) This application is divided from my pending application No. 153,809 now Patent No. 2,738,629 issued March 20, 1956.

The present invention relates to the sharpening of rotary cutters, principally those having cutting edges which may be geometrically defined as lying in a cylindrical surface. One important application of the invention is to apparatus for cutting leaf tobacco. In such apparatus leaf tobacco is compressed and fed through a mouthpiece and as it emerges is cut into thin slides by a cutter which may be a single reciprocating knife or may be a rotary drum carrying one or more knives. Particular problems of sharpening arise with apparatus in which such a rotary cutter is used since it is most desirable to be able to sharpen the knives without the waste of time involved in removing them from the drum. In fact the wear on the knives caused by the toughness of leaf tobacco makes it desirable to sharpen the knives of rotary cutters continuously while cutting is in progress.

In apparatus for cutting leaf tobacco it is necessary to vary the clearance between the cutting edges and the mouthpiece through which the tobacco is fed according to the quality of the tobacco. It has therefore also been necessary to provide adjustments by which a grinding wheel is moved to allow for the movement of the cutter. This is inconvenient in use and may lead to uneven grinding.

It is an object of the present invention to provide apparatus for cutting leaf tobacco in which adjustment of the relative positions of a rotary cutter and the mouthpiece does not disturb the relative positions of the cutter and a grinding device.

It is a further object of the invention to provide apparatus for cutting leaf tobacco in which a rotary cutter is continuously ground to a constant effective diameter.

Further objects and advantages of the present invention will appear from the following description of one embodiment, reference being made to the accompanying drawings in which:

Figure 1 is an elevation of one side of a complete machine;

Figure 2 is an elevation on a larger scale of part of the other side of the machine; and

Figure 3 is an enlarged elevation of the machine in section on the line IIIIII in Figure 2.

Leaf tobacco is fed into the space 2 between two converging conveyor belts 4 and 6 which carry the tobacco to a mouthpiece 8 and at the same time compress it so that it is driven through the mouthpiece as a plug. As the plug emerges it is shredded by knives 10 on a drum 12 which is turned on a shaft 13 by a drive 14. The out ting edges of the knives all lie in an imaginary cylindrical surface which is indicated at 16 and they are very slightly inclined to lines parallel to the axis of the drum so that The shaft 13 carrying the drum is carried in bearings 30 at the ends of arms 32. These arms are each pivoted at 34 to the base of the machine and together form a support both for the drum and for a bed 36 on which slides a carrier 38 forming the bottom of a grinding device 40. The support can rock to and from the mouthpiece under the control of a linkage operated by a handwheel 42. This linkage includes a shaft 44 which carries on each end a crank 46. The cranks are each connected to an arm 32 by a pivoted link 48, and are arranged so that the small movement of the drum necessary to adjust the clearance between the cutting edges and the mouthpiece is brought about by movement of the cranks through an are slightly to one side of a dead centre position. The shaft 44 is turned by the handwheel 42 through a worm drive 50 and bevel gears 52. Movement of the cranks in the direction to reduce the clearance is limited by a stop 54.

If it is desired to inspect the mouthpiece 8, the shaft 44 can be turned to move the cranks 46 into a position 56 in which the arms 32 are rocked the full distance permitted by the throw of the cranks.

The grinding device 40 is described in detail and claimed in my copending application No. 153,809 from which the present application is divided. This grinding device incorporates a disc grinding wheel 58 mounted to turn on a shaft in a housing 62. This wheel 58 is caused to sharpen the full length of the cutting edges of the knives 10 by reciprocation of the carriage 38 on the bed 36.

As the cutting edges of the knives 10 are continuously sharpened, metal is worn away from them, and at the same time the rim of the wheel 58 is also worn away. Arrangements are made to compensate for this wear and so maintain a constant diameter of the cylinder 16. The knives 10 are progressively fed outwards on the drum 12 by mechanism indicated generally at 66. A particular mechanism for carrying out this feeding is described and claimed in my copending application No. 152,698 now Patent No. 2,614,596 issued October 21, 1952. This mechanism operates to move the knives outwards a small distance each time the carriage 38 reaches the end of a stroke and the wheel 58 is just clear of the cutter. The housing 62 and with it the wheel 58 is movable on the carriage 38 and is gradually fed towards the drum 12. At the same time the contour of the rim of the wheel 58 is maintained by dressing with a diamond (not shown).

I claim:

1. Apparatus for cutting material such as leaf tobacco comprising, in combination, a frame, a rotary cutter having at least one cutting edge to describe a cylindrical path during rotation of the cutter, a mouthpiece in said frame through which material is fed, arms bearing said rotary cutter pivotly, mounting the cutter to the frame for movement relative to the mouthpiece, and an adjustment means adapted to move said arms both to adjust finely the position of said cutter when close to said mouthpiece and to move said cutter well clear of said mouthpiece for inspection, said means comprising a shaft rotatably mounted in said frame, means including a gear train for rotating said shaft, a crank fixedly mounted on said shaft, linkage means interconnecting the eccentric end of said crank and said arms bearing the rotary cutter, said crank and said linkage means being normally positioned in a close to dead center relationship whereby rotation of said shaft produces a rocking movement of said rotary cutter relative to said mouthpiece.

2. Apparatus as claimed in claim 1 and further comprising a grinding means for continuous sharpening of said rotary cutter and rigidly mounted to said arms bearing sa'id rotary cutter, such that adjustment of the rotary cutter with respect to said mouthpiece is effected without disturbance of the relative positions of the cutter and said grinding means.

on the side of said cutter remote from said mouthpiece and movable on said support in a direction parallel to the axis of rotation of said cutter, and means operatively connected to said support for gradually moving said support whereby the clearance between said mouthpiece and said cutter may be finely adjusted Without disturbance of the relative positions of said cutter and said grinding means.

References Cited in the file of this patent UNITED STATES PATENTS Van Berkel Nov. 17, 1903 Molins May 24, 1932 Rundell Nov. 22, 1932 Cole Feb. 14, 1933 Van Berkel May 9, 1933 Molins et a1 Oct. 31, 1933 Thomas May 29, 1934 Molins Jan. 21, 1936 Philippe Sept. 5, 1939 Schreiber Mar. 22, 1949 Dearsley Dec. 26, 1950 Molins et al. Dec. 26, 1950 FOREIGN PATENTS Denmark Feb. 22, 1927 

